The invention relates to a transmission with a hydraulic control system for the controlled pressurization of actuating members that are arranged on at least one rotary shaft, with a hydraulic control device that has at least two control device plates, an intermediate layer between the control device plates, and a hydraulic connection between the hydraulic control device and the rotary shaft.
For the hydraulic control of actuating members on rotating transmission shafts of a vehicle it is necessary to provide a reliable and essentially fluid-tight connection between a stationary control device and a rotary shaft.
It is therefore the object of the present invention to provide a transmission of the kind introduced above with a fluid connection of low complexity and high reliability, so that the reliable operation of the vehicle is not put at risk by hydraulic failures or break-downs of the fluid system.
In a transmission according to the invention, the foregoing objective is met by an arrangement where the connection between a stationary control device and a rotary shaft (subsequently called rotary connection) consists of two essentially coaxial tubular elements that are at one axial end seated in receiving portions of the shaft and at the opposite axial end received in a stepped bore hole of one of the control device plates, where the intermediate layer serves as axial constraint of one of the tubular elements.
It is advantageous if the stepped bore hole has at least two axial sections of different diameter and if each of the two at least approximately coaxial tubular elements is at one axial end seated in a respective bore-hole section in a fluid-tight arrangement by means of a seal.
It is also advantageous if the radially inner tubular element receives a flow of fluid through an opening in the intermediate layer.
It is further of practical advantage, if the radially outer tubular element receives a flow of fluid through a passage that leads from a radially off-centered channel in a control device plate through an oblique or transverse bore hole into an intermediate space of the stepped bore hole and into the tubular passage channel between the two tubular elements. The oblique or transverse bore hole can be drilled with the tool entering from the outside of the control device plate through the stepped bore hole that receives the tubular elements or from the side facing the intermediate layer. By selecting an appropriately small diameter size for the oblique or transverse bore hole, the latter can have the effect of a throttle or shutter. The same applies to horizontal bore holes (i.e., parallel to the shaft), e.g., in the intermediate layer.
According to a further concept of the invention, it is advantageous if the oblique or transverse bore hole leads into a spatial portion, such as the aforementioned intermediate space, that is arranged between the two seals of the tubular elements.
In transmissions with a hydraulic control system for the controlled pressurization of actuating members that are arranged on at least one rotary shaft, with a hydraulic control device that has at least two control device plates, an intermediate layer between the control device plates, and a hydraulic connection between the hydraulic control device and the rotary shaft, the objective of the invention is met furthermore by an arrangement where the rotary connection consists of two essentially coaxial tubular elements that have at one axial end a sealed engagement in receiving portions of the shaft and are received at the opposite axial end in a stepped bore hole of an extension of the control device. At least two channels are arranged essentially parallel to each other in the extension and are connected by the tubular elements to channels that run inside the shaft.
It is further advantageous, if the stepped bore hole in the extension has at least two axial sections of different diameter size and if each of the two at least approximately coaxial tubular elements is at one axial end seated in a respective bore-hole section in a fluid-tight arrangement by means of a seal. It is also of practical benefit, if the stepped bore hole has sections of four different diameter sizes. A further practical advantage arises if the stepped bore hole cuts into the two channels of the extension.
According to a further concept of the invention, it is advantageous if at least one transition between sections of different diameter in the stepped bore hole is designed as a shoulder that serves as an axial constraint of a tubular element.
It is practical if the radially inner tubular element is connected to a first channel of the extension and supplied with a flow of fluid by a section of the stepped bore hole.
It is advantageous if the fluid enters the radially outer tubular element from a second channel in the extension (where the stepped bore hole cuts into said channel) by way of a space between the seals of the two tubular elements that leads into the tubular passage channel between the coaxially arranged tubular elements. It is advantageous if the channels in the extension are closed off by cover plugs.
In accordance with a further concept of the invention, it is of practical benefit if a portion of a cover plug is configured to take up axial forces acting in the direction towards the shaft, so that the plug can serve as a constraint for a tubular element.
According to a further concept of the invention, it is advantageous if at least one tubular element is axially secured by means of a holder element.
The holder element in a practical embodiment of the foregoing concept is configured as a sheet-metal piece with a fork that engages a groove of the tubular element. It is also of practical benefit if the holder element is fastened to the control device, e.g., by a screw connection.
The novel features that are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operations, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.